Inertia controlled shock absorber



Feb. =12, 1935'.

T. R. VARNELL INERTIA CONTROLLED SHOCK ABSORBER Filed Jan.- 50, 1933 5 Sheets-.Sheet l l 32mg. ,y im www" T. R. VARNELL INERTIA CONTROLLED SHOCK ABSORBER Feb. 12, 1935.

Filed Jan. 3o`, 1953 5 sheets-sheet s A QM.

.mu UNK N Feb. l2, 1935.

T. R. VARNELI. 1,991,265

INERTIA ONTROLLE'D SHOCK ABSORBER Filed Jan. 30, 1955 5 Sheets-Sheet 4 I l ,I I 7'.' A?. Farine/.

Feb. 12, 1935. T, RA VARNELL 1,991,265

INERTIA CONTROLLED SHOCK ABSORBER Filed Jan. 30, 1935 5'Sheets-Sheet 5 9. 33M l www@ PatentedlFeb.v12k,`1935 y l f if l y yUNTE STAT-ES PATENTTL OFFICE 01,991,26511lld' f z V Q iNER'rIA ooNTRoLLnD snooii; Asonispn l Thomas Rosc'oe-Varnell; .(Jl'e'v'elakm, `Tennal Application Jaary, 1933,k serial No. 654,338* Y ke claims.' (014.l 18a-885-v y invention" relates `to v"shock absorbers'v Figure 6 isa-vertical cross lsectionftalxenon i which are Aespecially adapted for,v motor vehicles j the line 6 6 'offFigure 2,

and has for an object to providealsh-ock absorberA ..Figure 7 is a det 'lperspectivelviewlofl which will notinteriere' Withthe. freeymoveinent crankarm, l

5' of? therfwheelsy and axles of ra vehicle either up-` Figure 81s a detail perspective view of the stopgf- 5 wardl'yior' dmvinwardly,l but will prevent the .rapid vFigure 9 is 1an end elevation of. vone of they movement offthe body-either upward or downpistons, A f 4 i 4 ward;` r y i y y.Figure 10 is a perspective view vslriowing both A A furtherzobjectisto provide ashock absorber the identical intertting pistons'in separatedicony in which the flow' of fluid iscontrolled by 'means dition topdisclose thejconstruction thereoandl l0 vv j ofiaivalvepossessing inertia and which closes up-V Figure 1'1 is a reduced side elevation of the ivazrdlyfwhen` the body of the;y vehicle'` is being' acshock'absorber lapplied to the frame and axle ofi 1 cel'erated` downward and closes downwardly when avehicle.` n n f .the bbdy'ds' being accelerated upward and in either Referring now to 'the drawings in which: like' Y' l5 closed .position-. operates to check the oil flow charactersot reference designate similar partsin, 15 t f sharply, the result being that the shock absorber. the various views-ldesigriatesan upright b0115- acts; toy impede suddenv protracted verticalmove-- ing havingaremovable cover plate llsecured by mentor (rebound, of the'vehiclebody while at., screws l2 threadedy inytobossesl;` carried. bythe the same time it permits theV springs ',tofunction housing.'` f

'U in thenormalmanner. to 'absorb shock. The hO'llSiIlg prvidedatlthe front,` neallillil 29 l yA further object isato' providea shock absorber top, with a transversecasing'llwhich is provided having a valve which oftersilittlel ornoresistance with bearings V15 fol the Shaft-16 0f vthe rQkarm toy opening; or closing while underoil pressure. y l6 1'. vThelcasing andy the housingYi,ccnmml'inie'ate,v Afurther object isto providea shockv absorber asbestgshown in Figurel, and constitute yare'ser-y 254 embodying opposed cylinders and pistons therein Voir for oil;l Cast enblocwithv theyhousing and- 25 30V tent, the parts being so arrangedas to provide operated fby4 movement. of; afrocker arm`A and Casing iS apailf 0f-longtlldhavlaline@i Cyil'idelSk adapted to: pass a fluid through openingswhich 1718116.v 13, vthek formerbeing closedl at-'its outer are controlled by a valve possessing inertial and 81H13.-` by an integral 1 Wa1f1119 and-'the' 'latter being nmited in `movement to; a `predetermined ex' closedgbyfva threaded cap 20p.. Both Cylinders 'communicate at their innerends with they casr- 30, compactness'of constructionv and sensitiveness of flgjand the Cylinders are also iilled` withlfroil.` f action., ,y y .l ,"Ihe'bottoinof the housing is closedbyac'overV Y With? the aboveandother objects in view the` 2l Which S Secured by means; 0f;` SGreWs `22,431@- l invention consistsi'n certain novel-details ofecen-1 removal ofA- which permits accessvto .the interiorl struction and combinations of partslhereinafter Ofvthe hOUSIlE- ThG-OD'COVGIT- llmay beffen-loved 35;l` fully describedl andY claimed'.

D by removalfof the screws l2 to afford access In the accompanying drawings forming a part 'the interior 0f the hOllSng and the asirlg. PTM- ofgthis specication, i top cover is provided with a filling opening. ,235

FigureI 1 is. a vplan viewl with the cover removed, i

Figure2vis avverticallongitudinal sectiontaken v. on theime: 2 2 of Figure. 1v and showing the opill-llecllllg laterally -flfm v90th Cylmders *are lposed Cyndersandpistons, l twothl'eaz'iedA 1ugs-r27 which takestudgboltsy Figure 3 is a horizontal section taken on" the for attach-lng theshock absorber@ the'fram-ezg line 3-3 of Figure 2- showingthe 'oil passages of the'vemcle o `i d t vth h in ,a 11 u al r The :cylinders are provided, respectivelmlwith: an 'por-s m e ous g, s We' ls le V Ve o hollow pistons 3()y and 31 which are identicalv incontrolling HOW 0f the lllpdthouh thepollaml i, kconstruction and are counterparts of each other passages `and are best show-n in Figure l0. v`Eachfpist'onais f the sneek absorber- Whhlislolsefl.byA a threaded plugziandthe t bottom. covenlis provided with a drainopening(25Y 49s,

lwhicliiis closedby a threadedplug. v

.50 Figure 4A is a crosssection taken onfthe line la-fla' provided at its Closed end with a pairof longitudi-,- 50'! of. l'igure 1v showing the valve -in :normal vopen nal caps 32K, vOneof Whichis equipped with agvlfmgirlv position,A f t tudinal slot 33 and the other of which is equipped,v

Figure 5 is a vertical section taken on theline near the'extrerne end,with a tongue 34. The pis- 5 5 of Yligurerl showingthe valve in the; saine tons interiit, the tongue of vonevextending,througlfrV PQSinl 35:1 Showilrl Figure 42 thefslot 3.3y ofthe other.y Eachpistonisrprovided, 55 ;y

between the ears, with a lug 35 and when the pistons are assembled these lugs confront each other `and receive between them the circular head 36 of a crank 37, best shown in Figure 2, for actuating the pistons as a unit.

For holding the pistons tightly against the head 36, a spring 38-is housed in the slot 33 of each piston and surrounds a pin 39, one end of which is fitted in an opening 40 in the ear, as best shown in Figure 3. The pin is provided with a stop collar 41 that engages the end wall of the slot. The spring expands against the tongue 34 of the mating piston and urges the tongue toward the op` posite end of the slot 83 so that both pistons are yieldably confined snugly agains'tthe head 36 .of the crank 37. The pins 39 prevent any great separation of the piston lugs from the crank head.

By referring particularly to" Figures 4 and 5, it`

` bushing, as shown` in plan in Figure Band in y'elevation'in Figures 4 and 5; These four openings are drilled radially Aand accurately at 90 apart in a planeata right angle to the axis of the bushing.r From these four openings, grooves are cut into the outer surface of the bushing parallel tof its' axis, two'of the grooves 50 ,and 51 being disposed diametric'ally opposite each other and running 'upward to an annular groove 52 formed in the bushing'as shown best in Figure 5. The other two grooves 53 and 54 are disposed diametrically opposite each other and run downward to 4()y as lshown in Figure 4.

`Formed in the bore 44 of the housingy is a port 56 which registers with the upper annular groove another annular groove 55 formed inthe bushing,

` 52fin' the bushing and which'opens into a passage 57 which leads into the outer end of the cylinder 18. Also formed in the bore of the housing isa port 58 which registers with the lower annulargroove 55`formed in the bushing and is con- 50, nected by a passage 59 tothe outer end of the cylinder 1.7.

A passage 60 connects the sump 61 between the inner ends of 'the cylinders with the chamber in thebottom of the housing, as best shown in Fige ures 2 and 6 so that oil pressure against the top and bottom of the valve 42 will be equalized and the valve will consequently offer little, if any, resistance Yto opening or closing, while-under pressure.,-v`

As the valve moves either upward or downward it closes the'before-mentioned openings 46, 47,

48 and 49 by movement 'of the groove 45 outfof register therewith. In the normally open position of the valve the fluid enters the groove attwo of the diametric opposite openings and leaves it at the other two diametric openings on the same level, as shown in Figures 4 and 5, so that there is no tendency of the valve to bind in the bushing and it will operate easily at all times.`

Attached to the valve is a weight 610 formed of lead-0r other metaL A cylindrical seat 62 is disposed snugly againstthe wall of thechamber in the bottom of the housing around the weight and serves as a retainer for a conical helical spring 63, 4the lower end of which is supported upon aange 64. at the bottom of the seat andy the upper end of which is engaged underneath a flange 65 formed at the top of the Weight.

The weight is provided with an axial opening 66 which loosely receives the valve bushing 43 andthe valve 42 and the latter is provided with a reduced threaded extension 67, which extends throughr an aperture 68 in the weight and is equipped with a nut 69 and washer 70. A key 71 is driven into a suitable keyway in the extension and bore of the aperture 68 and prevents relative turning of the valve and weight so that the nut 69 may be screwed tight to rigidly secure the weight to the valve. f

It will'be observed-that the spring 63 is disposed outside the weight and this makes possible an adjustment of the spring tension, about to be described, and also produces a great length of wire in the spring to make very slow the natural rate of oscillation of the Weight and valve. It will also be observed that the valve bushing 43 extends below the center of gravity/of the weight and also of the valve so that side sway'of the vehicle will not bindthe Valve in the bushing.`

For adjusting the tension of the spring, the seat maintain the valve open, that' is, with'the groove;

45 in registration with the four openings 46, 47, 48 and 49. A tubular threadedy follower 76 is provided with a hexagonal wrench bore 77 by means of which the'follower is screwed down thethreaded wall 78 of thew'ell into contact with the barr nut to hold the barrel'nut in4 place.

For controlling and limiting movement of the valve,- the crank 37 is provided with a hub 79 which is rigidly secured to the rock shaft 16 by means of screws 80, as bestshown iny Figures 2 and 6. The hub is provided with a slot 81 which is disposed at a right angle to the axis of the hub and extends from the top to nearly the bottom of the hub. This slotr receives a spring metal crank arm metal plates 83 which are provided with alined openings 84'to rlooselyreceive. the shaft 16. The

. plates are oiset laterally, as shown at 85 in Figure 1, and directed at their extremities to lie flat upon each other and 'these fiat extremities 86 are riveted together, as shown at 87. vA `corrugated annular spring 88 Vencircles the vshaft between the plates and urges the plates apart to frictionally engage the side walls of the slot 8l in the hub, -asshown "in Figures 1 and 6 so that therock shaft turns the crank arm. v

A lip 89 projects laterally from the lower edge of oney of the extensions 86 and the lip` is provided with a slot 90 and preferably one edge of the lip is turned upwardly, as shown at 91, to stiften the lip. The lip is of suiiicient length to extend into the upper chamber of the housing 10 and overhang the f valve 42.

A stop link 92, best shown in Figure 8, is carried--by-the lip. The link is reduced at the top to form a stem 93 which is provided with kers 94 that 4permit o the stein being passed into the slot 90 and held by the lip. The link is uniformly enlarged at the bottom to provide a barrel 95, the peripheral wall of which is equipped with grooves eewmchextena paraueito the axis ofl theb'airei I and permit thevv passage ofoil-along thefbarrell! 1 stantially sanare' recess 97, `andl in' its` bottomv is equipped-withaslotf9 which communicates with larged-to 4ifo-rm a'housing `101 for the barrel 95v of the'stop link, and'y is closed by a cap 102 which limits upward inovement`-of the stop link'. AThe Capris provided with-'a central opening 103, whichsl-idablyreceives the stenir93 of the link. Resil ient bumper rings V104 and 105 are conned-in suitablelgrooves-i'n the bottom of the housing in the bottom ot the cap 102. vThese vrings l absorb fthe' shocks of impact ofv"thev"'s'top link when riioved"by the crank arm 82.,

- It will be observed thatthere is an axial opening` 1'06in the stopilinl stern. The purpose-of this is'to permit'the vvalvelzto be properly adjusted. To accomplish `this a' small wirefeeler is inserted' through f the aperturey 1061u`nti1 the feeler restsfon the' kvalve "i 2}."I'lie barrel nut 74"l isftloe'nv adjusted to so disposefthevalve that vwhen tlocvalve stop link 92 is moved either upward or'd'cwnwardV no motion is'imparted to` the valve.

It will also be observed that the passage 60 f and the opening 73 in' theliousing afford freeA circulation of'the oil between the weightv cham'- be'r n# the bottom ci the valve housing 10 .y and the reservoirl in the top'of the 'housing so that pressure' against the top and willbe equ'alized.v

A' T'ne sojcclzy absorber Ais fraineZQby-"means ofthe bolts or lagscrews 28 and the vrocker arnifl" s'connected 4to the `axle 1 1." The operation isas follows:

by aj link 107 and bracket 108, shown in Figure kWhen the vehicle passes over small inequalities inthe road surface, the axle isA rapidlyy vibrated up and'down within a snrallrange of movement,

and imparts to the rcclzerl' and pistons 30 and 31' a correspondingmovement. 'Howeven because there is little upward ordownwar'd movement' ofthe vehicle body, the heavyweighted valve 42 is only .slightly influenced and 'remains in normal open position. lin this position oflthe valve, "thereV free communication between the compression spaces ofy both cylindersl by way oi the passages 57, 59,l 'thegrooves and openings in the Valve bushingand the groei/e145 in 'thekvali/e,

'-,thereby permitting afree vibration of the pistons' Without interference with the resiliencyk of' the vehicle springs 109. y i Should the vehicle wheels encounter 'a hump of sufiicient height to produce'a. marked upward Y movement of the aide,v itisbrought nearerithe vehicle 'body' v compressing` the vehicle eorinas beyond theiry neutral position. Simultaneously, the hub 179 is turned and Shifts thepistons as a unitin a directionV toward the outer end of` theA cylinder 18. -A's longjas the axle .ofthe vehicle" continues to move upward in relation tothe body and' thus further compress the vehicle spring, the

weighted valve' cannot lag ybehind ajpossible up-y ward nioveinentof the body and close the valve downwardly because the rocker arm S2ywhich m i e j aweighted valve for controlling said passage and` tends to'fturn with `tliefhub179 has `lifted the thefvalve from' closing in one directionr but leaves bottom of Athe valve y the Vehicle springr has reached its maximumy ex-4 i secured toy the n body valve'stop link 92H50 thatr vthelink"restsfagainst the upper? shouldery *100; of" the; valvef andi holds 'the valve openj Hence there 'isf no 'interference whatever with thefupward'movenientof. the ax1e .1." l i `@But iininedi'aely 'after the-,avehicle axle #has ceased to i inoveK upward 'relative' to 'the body, i the .spring having reached its maximum compression, the liubyI9'reverses its direction'of rotation-and simultaneously-inoves the rocker 'arinffSZ which depressesrtliestop link 92freein`g`the valve'so that it now lags behindthe continued'upwardA acceleration ofthe-vehicle bodyfandV closes the lvalve downwarditoseal ti'iebopenings 46, 47, 48 and 49.

The closing of v*the valveirnpedes the return offthe oi'lfunder pressure through the vpassages Y.S9-and 57tothe-.cylinder l'so that the'rocker arrnv is held againstmrapid movementnv and"`the rebound ortendencyofltlie vehiclelto be projectedviolcntly upwardis positively prevented.` `llien the slowr upwardinoveinent of` tl'iefveliicle body has continued until the vehicle' spring has reached its neutrai' or normal position-y there' yisf no-i further up# ward acceleration ciy lthe body and "hence, no

further tendency for-'the inertia; of `tlie weighted valve"` to hold it 'inVK aclosed'lpositionand it is returned-toits open position by the kvalvespring When in thefroadbe'df of sufiicient depthio permit a marked-a downward '-rnoveinent' 5 of the vehicle wheels, causing the' axle to move further-away from the vehiclebody Yand?,expandingthe vehicle beyond their neutral positionlgthe above described stepsfoi'operaticn-are reversed.y *i 1n this instance, i the valve stop link engages the xlower shoulder -lilti'on' the valve `and prevents upward closing of the valve and consequent inter-ference with the free movementof'the vehicle axle until pansion,'but' the ,stop link then moves upward fre`eiii-etlevalve` so that its ownyinertia'opposing the'j downwardly kaccelerating vehicle body closes lthevalve upward andthereby impedes the downward'movement-foi the body.'

From thiseiiplanation of the,operation, itis l evident thattliis shockabsorber so operatesthat it allows perfectlyv free movement of the/wheels of, vehicle but very effectively" preventsI objec-f .What is claimed is:v l i l. A sliock absorber' for vcontrolling ,movement tonable movement of the body of the vehicle;v l f' the-vehicle axle encounters a depression fio of" relatively movable'parts comprising a fiuidv containing ineinber` adapte'dtofbe attached to one of the parte, a "fluid containingcylinder'carried by the member, ported means vcarried by. the" member establishing communication between op? posite endsv of Y the cylinder, .a piston vin the cylin-` der, inea-ns for-operatively connecting the piston to` be moved by lthefctherof'fsaid parts, a weighted spring'vpressed valveinsaid member rpossessing.` inertia 'and adapted to'controlrsaid-ported means,

and means-responsive to movement lof the piston and adapted to hold tlievalve 'against movementv in one direction while permitting the Valve tovmove in the opposite `direction. i

shock absorber forcontrolling` movementv of relatively movable parts vcomprising a member adapted'to be attached to one ortho ypar-ts vand having fluid-"containing opposed cylinders and P a passage establishing communicationbetween said cylinders, a piston in eachcylinden'means carriedby the member for operatively connecting the 'piston to be'n'ioveri` by the otherv of said parts,

.Soil

the flow of fluid therethrough, a spring adapted to support the weighted valve to occupy a substantially balanced open position with relation to said passage whereby the valve will be influenced by its own inertia. to close the passage upon predetermined movement of said parts, and means responsive tomovement of the piston and adapted to hold the valve against movement inv one direction while permitting the valve to move in the opposite direction. v

3. In a uid check shock absorber, ahousing, acylinder carried thereby, a piston in the cylinder, saidA housing` and said cylinder being filled with fluid, a ported passage in the housing for establishing circulation ofthe uid under irnpulse of the piston, a vertically disposed valve in the` housing controlling said passage, a `weight carried by the lower end of the valve, a spring surrounding the Weight, means carried by the housing for adjusting they tension of the spring to yieldably support the valve in normally open position, and means responsive to movement of the piston adapted to hold the valve against movement in one direction while permitting the valve to move in the opposite direction.

4. In a fluid check shock absorber, a housing, a cylinder carried thereby, a piston in the cylinder, said housing and said cylinder being lled with iluid, uid passages leading from the ends of the cylinder and terminating in superposed ports in the bore of the housing, a valve bushing in said bore having superposed annular passages registering with said ports andhaving vertically disposed passages about 90 apart and extending to a central point between said annular passages, a weighted valve mounted in said bushing and having an annular groove in communication with said vertically disposed passages, and a spring adapted to support the Weighted valve to occupy a substantially balanced open position with relation to said passages whereby the valve will be iniiuenced by its own inertia to close the passages upon predetermined movement of the valve.

5. In a fluid check shock absorber, a housing, alined cylinders carried thereby, pistons in said cylinders, said housing and 4said cylinders being filled with uid, a rocker arm shaft carried by the housing, a crank carried by the Shaft for reciprocating both pistons, ported passages in the housing for establishing circulation of the fluid in the ends of the cylinders under impulse of the pistons, a vertically disposed valve in the housing controlling said passages, a weight carried by the lower end of the valve, a spring supporting the weight to position the valve to occupy a substantially balanced open position with respect to said ported passages, a crank arm carried by said rocker arm shaft and extending into said housing to overhang the valve, and a stop link carried by the free end of the last named crank arm and operatively connected to the upper end of v said valve to hold the valve against movement in one direction while permitting the valve to move in the opposite direction.

6. In a fluid check shock absorber, a housing, a cylinder carried thereby, a piston in the cylinder, said housing and said cylinder being lled with fluid, a ported passage in the housing for establishing circulation of the fluid under imv pulse ofthe piston, a vertically disposed valve in ,the housing controlling said passage, a weight carried by the lowerend of the valve, a seat in the housing surrounding the weight and spaced therefrom, a spring interposed between the seat ,and the `weight and yieldably supporting the:

weight, a vertically disposed rod carried by the seat and threaded at its upper end, there being a well formed in said housing laterally of the axis thereof, and a barrel nut seated in thewell and having a screw thread engagement with the upper end of the-stand rod for adjusting the tension of the spring to support the valve to occupy a substantially balanced open position with relation to said passage. i

7.--In a uid checkshock absorber, a housing, a cylinder carried thereby, a piston kin the cylinder, said housing and said cylinder being filled with fluid, a ported passage in the housing for establishing circulation of the fluid under impulse of the piston, a spring-pressed weighted Valve in the housing controlling said passage, a rocker arm shaft carried by the housing, acrank xed to the shaft and engaging the piston for actuating the piston, a hub 0n the shaft havinga slot formed at a right angle to the axis of the shaft, a second rocker arm'carried by the shaft including a pair of resilient spaced plates perforated to receive the shaft and seated in sald slot, said plates being terminally equipped with a lip disposed to overhang the valve, a spring encircling said shaft between said plates. and pressing the plates apart to frictionally ,engage the side walls of said slot whereby the shaft frictionally moves said ycrank arm,and a stop link carried by said lip and loosely engaging'the upper end of the valve, said link being adapted to hold the valve against movement in one direction while permitting the valve to move in the opposite direction. v

8. In a fluid check shock absorber, a housing, a cylinder carried thereby, a. piston in the cylinder, said housing and said cylinder being lilled with fluid, a ported passage in the housing for establishing circulation of the fluid under impulse of the piston, a vertically disposed weighted spring-pressed valve, in the housing controlling said passage, said valve having an annular groove near the upper end thereofa stop link including a stem'and a barrel disposed above said valve, said barrel having a recess in one side and having a slot in the bottom communicating with said recess, said reduced portion of the valve being passed into said slot, means responsive to movement of the piston for moving said stop link relatively to the valve, a housing for the stop link, a cap closing the housing, and having an opening slidably` receiving said stem, said cap limiting upward movement of said stop link, bumpers on the lower` face of the cap and on the bottom ofthe stop link housing for cushioning shock of impact of the stop link at each limit of movement, and shoulders formed on the valve at the ends of said reduced portion thereof, the bottom of said stop link being adapted to engage one of the shoulders at each limit of ymovement of the stop link and hold the valve against movement in one direction while permitting the valve tomove in the opposite direction. v

9. In a fluid check shock absorber, a housing, a pair lof alined cylinders carried vthereby closed at their outer ends and communicating at their inner ends, said housing and said cylinders being adapted to be filled with fluid, pistons in the cylinders eachhaving a pair of longitudinal ears on one end, the earsof both pistons interfitting, one ear of each piston being provided with a slot and the other earbeing provided with a tongue, the tongue of one pistontting inthe slot of the other piston, springs seated in the slots bearing against the tongues, lugs on the pistons, a

rocker arm, a. rocker farm shaftcarried byjthe housing, a. crank on the shaft having its free endv interposed between the lugs `and adapted to move the pistons as a unit, the springsHresisting sep-g` eration of the said. free end of the crank fromy the lugs, there being passages in the housing andr cylinders opening into theends of the `oyliriders Vfor permitting circulation of the fluid -by movelthe opposite direction.

mentof the pistons, under'irnpulse of the crank,

ke1,'vveighted spring-,pressed valve inthe housing r controlling circulation of the iiuid, aindrneans're-rk THOMAS Roscoe:I VARNELLy [x.,s.i 

